In the beginning of industrial revolution, especially in 1960 to 1970, automated machines wear controlled by electromechanical relays. These relays wear hardwired together inside the control panel. Many of the times the control panel was so huge that it would cover entire wall. Every connection in the relay logic must be connected. Wiring is not always perfect; it takes time to troubleshoot the system. This is very time consuming Process. On top of that the relays have limited contacts. If modification is required, the machine has to be stopped, the space may not be available and wiring has to be traced again to accommodate changes. The control panel can only be used for the particular process. It cannot be changed immediately to a new system. It has to be redone. In terms of maintenance, an electrician must be well trained and skilful in troubleshooting the control system. In short, the conventional relay control panel is very inflexible.
DOI: 10.17762/ijritcc2321-8169.15020
